Re: [PATCH bpf-next v3 2/3] selftests/bpf: Add tests for string kfuncs

[Jiri Olsa <olsajiri@gmail.com>]

On Mon, Mar 24, 2025 at 01:03:29PM +0100, Viktor Malik wrote:
> The tests use the RUN_TESTS helper which executes BPF programs with
> BPF_PROG_TEST_RUN and check for the expected return value.
> 
> Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
> Signed-off-by: Viktor Malik <vmalik@redhat.com>
> ---
>  .../selftests/bpf/prog_tests/string_kfuncs.c  | 10 ++++
>  .../selftests/bpf/progs/string_kfuncs.c       | 58 +++++++++++++++++++
>  2 files changed, 68 insertions(+)
>  create mode 100644 tools/testing/selftests/bpf/prog_tests/string_kfuncs.c
>  create mode 100644 tools/testing/selftests/bpf/progs/string_kfuncs.c
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/string_kfuncs.c b/tools/testing/selftests/bpf/prog_tests/string_kfuncs.c
> new file mode 100644
> index 000000000000..79dab172eb92
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/string_kfuncs.c
> @@ -0,0 +1,10 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (C) 2025 Red Hat, Inc.*/
> +#include <test_progs.h>
> +#include "string_kfuncs.skel.h"
> +
> +void test_string_kfuncs(void)
> +{
> +	RUN_TESTS(string_kfuncs);
> +}
> +
> diff --git a/tools/testing/selftests/bpf/progs/string_kfuncs.c b/tools/testing/selftests/bpf/progs/string_kfuncs.c
> new file mode 100644
> index 000000000000..9fb1ed5ba1fa
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/string_kfuncs.c
> @@ -0,0 +1,58 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (C) 2025 Red Hat, Inc.*/
> +#include "vmlinux.h"
> +#include <bpf/bpf_helpers.h>
> +#include "bpf_misc.h"
> +
> +int bpf_strcmp(const char *cs, const char *ct) __ksym;
> +char *bpf_strchr(const char *s, int c) __ksym;
> +char *bpf_strchrnul(const char *s, int c) __ksym;
> +char *bpf_strnchr(void *s, u32 s__sz, int c) __ksym;
> +char *bpf_strnchrnul(void *s, u32 s__sz, int c) __ksym;
> +char *bpf_strrchr(const char *s, int c) __ksym;
> +size_t bpf_strlen(const char *s) __ksym;
> +size_t bpf_strnlen(void *s, u32 s__sz) __ksym;
> +size_t bpf_strspn(const char *s, const char *accept) __ksym;
> +size_t bpf_strcspn(const char *s, const char *reject) __ksym;
> +char *bpf_strpbrk(const char *cs, const char *ct) __ksym;
> +char *bpf_strstr(const char *s1, const char *s2) __ksym;
> +char *bpf_strstr(const char *s1, const char *s2) __ksym;
> +char *bpf_strnstr(void *s1, u32 s1__sz, void *s2, u32 s2__sz) __ksym;

hi,
I don't think above declarations are necessary, it should be all
in vmlinux.h already

jirka

> +
> +char str1[] = "hello world";
> +char str2[] = "hello";
> +char str3[] = "world";
> +char str4[] = "abc";
> +char str5[] = "";
> +
> +#define __test(retval) SEC("syscall") __success __retval(retval)
> +
> +__test(0) int test_strcmp_eq(void *ctx) { return bpf_strcmp(str1, str1); }
> +__test(1) int test_strcmp_neq(void *ctx) { return bpf_strcmp(str1, str2); }
> +__test(1) int test_strchr_found(void *ctx) { return bpf_strchr(str1, 'e') - str1; }
> +__test(11) int test_strchr_null(void *ctx) { return bpf_strchr(str1, '\0') - str1; }
> +__test(0) u64 test_strchr_notfound(void *ctx) { return (u64)bpf_strchr(str1, 'x'); }
> +__test(1) int test_strchrnul_found(void *ctx) { return bpf_strchrnul(str1, 'e') - str1; }
> +__test(11) int test_strchrnul_notfound(void *ctx) { return bpf_strchrnul(str1, 'x') - str1; }
> +__test(1) int test_strnchr_found(void *ctx) { return bpf_strnchr(str1, 5, 'e') - str1; }
> +__test(11) int test_strnchr_null(void *ctx) { return bpf_strnchr(str1, 12, '\0') - str1; }
> +__test(0) u64 test_strnchr_notfound(void *ctx) { return (u64)bpf_strnchr(str1, 5, 'w'); }
> +__test(1) int test_strnchrnul_found(void *ctx) { return bpf_strnchrnul(str1, 5, 'e') - str1; }
> +__test(11) int test_strnchrnul_notfound(void *ctx) { return bpf_strnchrnul(str1, 12, 'x') - str1; }
> +__test(9) int test_strrchr_found(void *ctx) { return bpf_strrchr(str1, 'l') - str1; }
> +__test(0) u64 test_strrchr_notfound(void *ctx) { return (u64)bpf_strrchr(str1, 'x'); }
> +__test(11) size_t test_strlen(void *ctx) { return bpf_strlen(str1); }
> +__test(11) size_t test_strnlen(void *ctx) { return bpf_strnlen(str1, 12); }
> +__test(5) size_t test_strspn(void *ctx) { return bpf_strspn(str1, str2); }
> +__test(2) size_t test_strcspn(void *ctx) { return bpf_strcspn(str1, str3); }
> +__test(2) int test_strpbrk_found(void *ctx) { return bpf_strpbrk(str1, str3) - str1; }
> +__test(0) u64 test_strpbrk_notfound(void *ctx) { return (u64)bpf_strpbrk(str1, str4); }
> +__test(6) int test_strstr_found(void *ctx) { return bpf_strstr(str1, str3) - str1; }
> +__test(0) u64 test_strstr_notfound(void *ctx) { return (u64)bpf_strstr(str1, str4); }
> +__test(0) int test_strstr_empty(void *ctx) { return bpf_strstr(str1, str5) - str1; }
> +__test(6) int test_strnstr_found(void *ctx) { return bpf_strnstr(str1, 12, str3, 6) - str1; }
> +__test(0) u64 test_strnstr_unsafe(void *ctx) { return (u64)bpf_strnstr(str1, 5, str3, 5); }
> +__test(0) u64 test_strnstr_notfound(void *ctx) { return (u64)bpf_strnstr(str1, 12, str4, 4); }
> +__test(0) int test_strnstr_empty(void *ctx) { return bpf_strnstr(str1, 5, str5, 1) - str1; }
> +
> +char _license[] SEC("license") = "GPL";
> -- 
> 2.48.1
>